

public class Main1 {
    class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode() {}
        TreeNode(int val) { this.val = val; }
        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }
    public boolean isSameTree(TreeNode p,TreeNode q){
        if(p==null&&q!=null||p!=null&&q==null){
            return false;
        }
        if(p==null&&q==null||p==null&&q==null){
            return true;
        }
        if (p.val!=q.val){
            return false;
        }

        return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
    }
}
